JPH05174849A - Phosphoric acid type fuel cell - Google Patents
Phosphoric acid type fuel cellInfo
- Publication number
- JPH05174849A JPH05174849A JP3338480A JP33848091A JPH05174849A JP H05174849 A JPH05174849 A JP H05174849A JP 3338480 A JP3338480 A JP 3338480A JP 33848091 A JP33848091 A JP 33848091A JP H05174849 A JPH05174849 A JP H05174849A
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- fuel
- air
- phosphoric acid
- air electrode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/02—Details
- H01M8/0271—Sealing or supporting means around electrodes, matrices or membranes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
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- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Fuel Cell (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】この発明は、リン酸形燃料電池に
関し、特に燃料ガスおよび空気の電極周辺でのシール機
能を損なわずに、生産性を向上できるリン酸形燃料電池
の電極構造に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphoric acid fuel cell, and more particularly to an electrode structure for a phosphoric acid fuel cell capable of improving productivity without impairing the sealing function of fuel gas and air around the electrodes. Is.
【0002】[0002]
【従来の技術】図15は例えば特開昭63ー16565
号公報に記載される従来のリン酸形燃料電池の一例を示
す電極シール構造の要部断面図である。図において、1
は白金等の貴金属を含有する燃料極触媒層3とこの燃料
極触媒層3を支えている多孔性基板5、例えば薄い炭素
基板とからなる燃料極、2は白金等の貴金属を含有する
空気極触媒層4とこの空気極触媒層4を支えている多孔
性基材5とからなる空気極、6は燃料極1と空気極2と
の間に配設されているマトリックス、7はセパレータで
ある。2. Description of the Related Art FIG. 15 shows, for example, JP-A-63-16565.
FIG. 4 is a cross-sectional view of a main part of an electrode seal structure showing an example of a conventional phosphoric acid fuel cell described in Japanese Patent Laid-Open Publication No. 2004-242242. In the figure, 1
Is a fuel electrode catalyst layer 3 containing a precious metal such as platinum and a porous substrate 5 supporting the fuel electrode catalyst layer 3, for example, a thin carbon substrate, and 2 is an air electrode containing a precious metal such as platinum. An air electrode composed of the catalyst layer 4 and a porous substrate 5 supporting the air electrode catalyst layer 4, 6 is a matrix arranged between the fuel electrode 1 and the air electrode 2, and 7 is a separator. ..
【0003】8は燃料ガス流路、9は燃料ガス流路8を
形成している燃料側多孔質板、10は空気流路、11は
空気流路10を形成している空気側多孔質板、12はセ
パレータ7に接合され、燃料側多孔質板9および空気側
多孔質板11のそれぞれの両端に配置された緻密質サイ
ドシール、13は燃料極1および空気極2のそれぞれの
周辺に配置されたパッキンシールである。Reference numeral 8 denotes a fuel gas flow path, 9 denotes a fuel side porous plate forming the fuel gas flow path 8, 10 denotes an air flow path, and 11 denotes an air side porous plate forming the air flow path 10. , 12 are joined to the separator 7, and dense side seals are arranged at both ends of the fuel side porous plate 9 and the air side porous plate 11, respectively, and 13 is arranged around each of the fuel electrode 1 and the air electrode 2. It is a sealed packing.
【0004】ここで、従来の上記リン酸形燃料電池は、
燃料極1と空気極2との間にマトリックス6が挟持さ
れ、その外側に、燃料ガス流路8と空気流路11とが相
対して互いに直交するように燃料側多孔質板9および空
気側多孔質板11が配置されてなる単位セルが、セパレ
ータ7を介して複数個積層して構成されている。Here, the above-mentioned conventional phosphoric acid fuel cell is
The matrix 6 is sandwiched between the fuel electrode 1 and the air electrode 2, and the fuel-side porous plate 9 and the air side are provided outside the matrix 6 so that the fuel gas channel 8 and the air channel 11 face each other and are orthogonal to each other. A plurality of unit cells in which the porous plate 11 is arranged are laminated with the separator 7 interposed therebetween.
【0005】このように構成された従来のリン酸形燃料
電池では、燃料ガス流路8および空気流路10のそれぞ
れから燃料ガスおよび空気を流入して発電を行う際に、
燃料極1および空気極2の周囲に配置されたパッキンシ
ール13が、マトリックス6と緻密質サイドシール12
とに挟持されて密着して、燃料ガス流路8および空気流
路10から供給される燃料ガスおよび空気の漏洩を防止
している。In the conventional phosphoric acid fuel cell thus constructed, when the fuel gas and the air are introduced from the fuel gas passage 8 and the air passage 10, respectively, to generate electricity,
The packing seals 13 arranged around the fuel electrode 1 and the air electrode 2 are the matrix 6 and the dense side seals 12.
It is sandwiched and closely adhered to and prevents leakage of fuel gas and air supplied from the fuel gas passage 8 and the air passage 10.
【0006】図16は例えば特開平1ー283771号
公報に記載された従来のリン酸形燃料電池の他の例を示
す電極シール構造の要部断面図である。この従来のリン
酸形燃料電池は、図15に示した従来のリン酸形燃料電
池におけるパッキンシール13に代えて、燃料極1およ
び空気極2のそれぞれの周辺部分にスクリーン印刷等の
手段によって高密度領域14を設け、この高密度領域1
4に電解質をあらかじめ含浸させてウエットシール部分
を形成し、燃料ガスおよび空気の漏洩を防止している。FIG. 16 is a cross-sectional view of an essential part of an electrode seal structure showing another example of the conventional phosphoric acid fuel cell disclosed in Japanese Patent Application Laid-Open No. 1-283771. In this conventional phosphoric acid fuel cell, in place of the packing seal 13 in the conventional phosphoric acid fuel cell shown in FIG. 15, the peripheral portion of each of the fuel electrode 1 and the air electrode 2 is made high by means such as screen printing. The density area 14 is provided and the high density area 1
4 is impregnated with an electrolyte in advance to form a wet seal portion to prevent leakage of fuel gas and air.
【0007】図17は例えば特開平1ー176665号
公報に記載された従来のリン酸形燃料電池のさらに他の
例を示す電極シール構造の要部断面図である。この従来
のリン酸形燃料電池は、燃料極1、空気極2およびマト
リックス6からなる3層の端部を樹脂によって注型など
により含浸一体化して端部樹脂15を形成し、燃料ガス
および空気の漏洩を防止している。FIG. 17 is a cross-sectional view of an essential part of an electrode seal structure showing still another example of the conventional phosphoric acid fuel cell disclosed in Japanese Patent Application Laid-Open No. 1-176665. In this conventional phosphoric acid fuel cell, the end portions of three layers consisting of a fuel electrode 1, an air electrode 2 and a matrix 6 are impregnated and integrated with a resin by casting or the like to form an end resin 15. To prevent leaks.
【0008】さらに、例えば特開平2ー139870号
公報に記載されるように、燃料極1や空気極2の端部を
それぞれフッ素樹脂系フィルムで覆い、熱融着によりシ
ール層を形成し、燃料ガスおよび空気の漏洩を防止して
いる。Further, as described in, for example, JP-A-2-139870, the ends of the fuel electrode 1 and the air electrode 2 are each covered with a fluororesin film, and a sealing layer is formed by heat fusion to form a fuel. Prevents leakage of gas and air.
【0009】[0009]
【発明が解決しようとする課題】従来技術のうちパッキ
ンシール13を用いるリン酸形燃料電池は、燃料極1お
よび空気極2のそれぞれの周囲に独立したシール材とし
てのパッキンシール13が必要となり、電極部分の部材
点数が増えてしまうという課題があった。つまり、この
種燃料電池では、所定の電圧が得られるように薄い電極
を通常200〜400枚程度積層する必要があり、電極
部分ごとにパッキンシール13を配置し、電極の積層作
業時間が大幅に増えてしまい、さらには積層部材点数が
多くなることにより、全ての部材積層に関する品質の確
保が困難となる。Among the conventional techniques, the phosphoric acid fuel cell using the packing seal 13 requires the packing seal 13 as an independent sealing material around each of the fuel electrode 1 and the air electrode 2. There is a problem that the number of members in the electrode portion increases. That is, in this type of fuel cell, it is necessary to normally stack about 200 to 400 thin electrodes so that a predetermined voltage can be obtained, and the packing seal 13 is arranged for each electrode portion, so that the working time for stacking the electrodes is significantly increased. Since the number of laminated members increases and the number of laminated members increases, it becomes difficult to secure the quality of all laminated members.
【0010】また、高密度領域14、端部樹脂15ある
いはシール層を形成するリン酸形燃料電池は、それぞれ
複雑で特殊な方法を採用してシール部分を製造する必要
があり、量産性に欠けるとともに、低コスト化が困難と
なるという課題があった。Further, in the phosphoric acid fuel cell in which the high density region 14, the end resin 15 or the seal layer is formed, it is necessary to manufacture the seal part by adopting a complicated and special method, which lacks mass productivity. At the same time, there is a problem that it is difficult to reduce the cost.
【0011】さらに、従来のリン酸形燃料電池では、燃
料極1および空気極2の多孔性基材5が炭素基板で構成
されており、何等かの運転状況の変化が生じた場合、電
気化学的電位が上昇し、炭素基板の腐食が起こるという
課題もあった。Further, in the conventional phosphoric acid fuel cell, the porous base material 5 of the fuel electrode 1 and the air electrode 2 is composed of a carbon substrate, and when some change in the operating condition occurs, the electrochemical There was also a problem that the electrical potential rises and corrosion of the carbon substrate occurs.
【0012】この発明は、上記のような課題を解決する
ためになされたもので、運転中の電極部分でのシール性
能を維持しつつカーボン腐食を抑え、電極の製造とセル
の積層作業における加工性・組立性を向上させ、燃料電
池の生産コストを低減できる、換言すれば、燃料電池の
量産時生産性を向上させるととともに高信頼性のリン酸
形燃料電池を得ることを目的とする。The present invention has been made in order to solve the above-mentioned problems, and suppresses carbon corrosion while maintaining the sealing performance at the electrode portion during operation, and processing in electrode manufacturing and cell stacking work. It is an object of the present invention to improve the productivity and assemblability and to reduce the production cost of the fuel cell. In other words, the productivity of the fuel cell during mass production is improved and a highly reliable phosphoric acid fuel cell is obtained.
【0013】[0013]
【課題を解決するための手段】この発明の第1の発明に
係るリン酸形燃料電池は、燃料極および空気極は、セパ
レータと同等の外形を有し、かつ燃料極および空気極の
少なくとも一方の極の両端部分のはっ水性を低減させ、
はっ水性を低減させた両端部分を電極シール部分とする
ものである。In the phosphoric acid fuel cell according to the first aspect of the present invention, the fuel electrode and the air electrode have the same outer shape as the separator, and at least one of the fuel electrode and the air electrode. The water repellency of both ends of the pole is reduced,
Both end portions with reduced water repellency are used as electrode sealing portions.
【0014】また、この発明の第2の発明に係るリン酸
形燃料電池は、燃料極および空気極は、セパレータと同
等の外形を有し、空気極の燃料ガス流路と平行な両端部
分に触媒層に代えて腐食防止層を設けるものである。Further, in the phosphoric acid fuel cell according to the second aspect of the present invention, the fuel electrode and the air electrode have the same outer shape as the separator, and the both ends of the air electrode parallel to the fuel gas passage are connected. A corrosion prevention layer is provided instead of the catalyst layer.
【0015】[0015]
【作用】この発明の第1の発明においては、セパレータ
と同等の外形を有する燃料極および空気極の少なくとも
一方の極の両端部分のはっ水性を低減させ、はっ水性を
低減させた両端部分を電極シール部分としているので、
セルを積層する際パッキンシール等のシール材が不要と
なり、積層部品点数が著しく削減される。また、燃料極
および空気極の少なくとも一方の極の両端部分以外の領
域にはっ水性処理を施すことにより極の両端部分のはっ
水性を低減できるので、通常の電極製造工程以外の処理
工程を必要とせず、燃料極や空気極の周辺部分に高密度
化領域を形成したり、燃料極や空気極の端部にシール層
を熱融着したりする特別なシール構造処理工程が不要と
なり、電極の生産性が向上される。In the first aspect of the present invention, the water repellency of both ends of at least one of the fuel electrode and the air electrode having the same outer shape as the separator is reduced, and the water repellency is reduced. Since it is the electrode seal part,
When stacking the cells, a sealing material such as a packing seal is not required, and the number of laminated parts is significantly reduced. Further, since water repellency of both end portions of the electrode can be reduced by performing water repellency treatment on a region other than both end portions of at least one of the fuel electrode and the air electrode, treatment steps other than the normal electrode manufacturing step can be performed. It is not necessary and does not require a special sealing structure treatment process such as forming a densified region in the periphery of the fuel electrode or air electrode, or heat-sealing a seal layer at the end of the fuel electrode or air electrode. The electrode productivity is improved.
【0016】また、この発明の第2の発明においては、
空気極の燃料ガス流路と平行な両端部分に触媒層に代え
て設けられた腐食防止層が、プロトンと酸素と電子とに
よる反応を抑制し、電気化学的電位の上昇を抑え、空気
極の空気流路の入口および出口部分の電気化学的電位を
低い電位に保ち、カーボン腐食を防止できる。According to the second aspect of the present invention,
Corrosion prevention layers provided in place of the catalyst layer at both ends of the air electrode parallel to the fuel gas flow path suppress the reaction between protons, oxygen and electrons, suppress the increase in electrochemical potential, It is possible to prevent carbon corrosion by keeping the electrochemical potential at the inlet and outlet of the air passage at a low potential.
【0017】[0017]
【実施例】以下、この発明の実施例を図について説明す
る。 実施例1.図1はこの発明の第1の発明に係る一実施例
を示すリン酸形燃料電池の電極シール構造の要部断面
図、図2の(a)、(b)はそれぞれこの発明の実施例
1における燃料極の単品状態を示す平面図および断面
図、図3の(a)、(b)はそれぞれこの発明の実施例
1における空気極の単品状態を示す平面図および断面図
であり、図において図15乃至図17に示した従来のリ
ン酸形燃料電池と同一または相当部分には同一符号を付
し、その説明を省略する。Embodiments of the present invention will be described below with reference to the drawings. Example 1. FIG. 1 is a sectional view of a main part of an electrode sealing structure for a phosphoric acid fuel cell showing an embodiment according to the first invention of the present invention, and FIGS. 2 (a) and 2 (b) are the first embodiment of the present invention. 3A and 3B are a plan view and a cross-sectional view showing a single state of the fuel electrode in FIG. 3, and FIGS. 3A and 3B are a plan view and a cross-sectional view showing the single-state state of the air electrode in Example 1 of the present invention. The same or corresponding parts as those of the conventional phosphoric acid fuel cell shown in FIGS. 15 to 17 are designated by the same reference numerals, and the description thereof will be omitted.
【0018】図において、3aは燃料極触媒層3のうち
はっ水処理を施したはっ水領域、3bは燃料極触媒層3
の未はっ水領域、4aは空気極触媒層4のうちはっ水処
理を施したはっ水領域、4bは空気極触媒層4の未はっ
水領域である。In the figure, 3a is a water repellent region of the fuel electrode catalyst layer 3 which has been subjected to water repellent treatment, and 3b is a fuel electrode catalyst layer 3
Of the non-water-repellent region 4a is a water-repellent region of the air electrode catalyst layer 4 that has been subjected to water-repellent treatment, and 4b is a non-water-repellent region of the air electrode catalyst layer 4.
【0019】ここで、上記実施例1では、燃料極1およ
び空気極2は、セル外形サイズ、即ちセパレータ7と同
一平面寸法に形成され、燃料極触媒層3および空気極触
媒層4が、燃料極1および空気極2のそれぞれの多孔性
基材5の面内全域に塗布形成されている。さらに、燃料
極1には、燃料ガス流路8に平行な両側部分で、その幅
が緻密質サイドレール12と同程度の領域において、未
はっ水領域3bが形成されている。また、空気極2に
は、空気流路10に平行な両側部分で、その幅が緻密質
サイドレール12と同程度の領域において、未はっ水領
域4bが形成されている。Here, in the first embodiment, the fuel electrode 1 and the air electrode 2 are formed in the cell outer size, that is, the same plane dimension as the separator 7, and the fuel electrode catalyst layer 3 and the air electrode catalyst layer 4 are the fuel. The electrode 1 and the air electrode 2 are formed by coating all over the surface of the porous substrate 5 respectively. Further, in the fuel electrode 1, the water-repellent regions 3b are formed in both side portions which are parallel to the fuel gas flow channel 8 and in the region where the width thereof is approximately the same as that of the dense side rail 12. Further, in the air electrode 2, unwater-repellent regions 4b are formed in both side portions parallel to the air flow path 10 in a region whose width is similar to that of the dense side rail 12.
【0020】リン酸形燃料電池に使用される触媒には、
通常バインダ材として、融点以上に加熱されるとはっ水
性を帯びてくるフッ素樹脂を使用している。そこで、多
孔性基材5に触媒を塗布した後、フッ素樹脂の融点以上
に加熱処理して初めてはっ水性が現れ、燃料電池のガス
拡散電極としての条件を兼ね揃えたものに仕上がる。ま
た、多孔性基材5に塗布した触媒を加熱焼成する際に、
はっ水処理をしない領域にだけマスキング等を施し、そ
の部分だけ温度が融点以下に保たれるようにすれば容易
に未はっ水領域を作製できる。The catalyst used in the phosphoric acid fuel cell includes
Usually, as the binder material, a fluororesin that is water-repellent when heated above the melting point is used. Therefore, water repellency does not appear until the catalyst is applied to the porous base material 5 and then heat-treated at a temperature equal to or higher than the melting point of the fluororesin, so that the fuel cell is finished under the condition that it also serves as the gas diffusion electrode of the fuel cell. Moreover, when the catalyst applied to the porous substrate 5 is heated and calcined,
By masking only the region not subjected to the water-repellent treatment and keeping the temperature below the melting point only in that region, the non-water-repellent region can be easily prepared.
【0021】つぎに、このように構成された燃料極1お
よび空気極2を用い単位セルを作製し、図4に示すよう
に、電極のシール性能試験を実施した。単位セルは、7
0cm角のセルサイズで構成され、マトリックス6を貫
通方向に漏洩してくるメタンを無くすために、マトリッ
クス6を2層構造とし、その間にあらかじめガス透過の
ないことを確認してある100μm厚のフッ素樹脂(P
FA)フィルム20を挟んだ構造とし、両側からスペー
サ21を介して所定の面圧を印加するとともに、各端面
にはそれぞれマニホールド22が配設されている。窒素
およびメタンの給・排配管には、流量計23、圧力計2
4、25、圧力調整バルブ26、27が設けられてい
る。Next, a unit cell was prepared using the fuel electrode 1 and the air electrode 2 thus constructed, and an electrode sealing performance test was carried out as shown in FIG. The unit cell is 7
The matrix 6 has a cell size of 0 cm square and has a two-layer structure for eliminating methane leaking through the matrix 6 in the penetrating direction, and 100 μm thick fluorine which has been previously confirmed to have no gas permeation between them. Resin (P
(FA) film 20 is sandwiched, a predetermined surface pressure is applied from both sides via spacers 21, and a manifold 22 is arranged on each end face. The nitrogen and methane supply and discharge pipes have a flow meter 23 and a pressure gauge 2
4, 25 and pressure adjusting valves 26, 27 are provided.
【0022】ここで、燃料極1側にはメタンを供給し、
空気極2側にはキャリアガスとして窒素を供給し、圧力
調整バルブ26を調整して窒素の圧力と流量は一定条件
(P2:300mmAg)にして、圧力調整バルブ27
を調整してメタン側の圧力(P1:0〜1000mmA
g)をかえて、空気極2側出口の窒素中のメタン濃度を
分析して電極端部分から漏洩してくるメタン量を測定し
ている。Here, methane is supplied to the fuel electrode 1 side,
Nitrogen is supplied to the air electrode 2 side as a carrier gas, and the pressure adjusting valve 26 is adjusted so that the pressure and flow rate of nitrogen are constant (P 2 : 300 mmAg).
The pressure on the methane side (P 1 : 0 to 1000 mmA
g) is changed to analyze the methane concentration in nitrogen at the outlet of the air electrode 2 to measure the amount of methane leaking from the electrode end portion.
【0023】図5に示す測定結果から、この電極構造で
は、電極端部からのガス漏洩量が多く、マトリックス6
にリン酸を含浸させた状態でも電極端部からのガス漏洩
量は無視できない量であることがわかった。このこと
は、電極端部に、はっ水性を付与していないにもかかわ
らず、高密度化処理等を施していないために比較的気孔
径の大きな部分が残っており、リン酸がこの比較的気孔
径の大きな部分にまで浸透できないからと推測される。
即ち、このような電極シール構造では、リン酸浸透によ
るウエットシール機能は実現できないことになる。From the measurement results shown in FIG. 5, in this electrode structure, the amount of gas leaked from the electrode end was large, and the matrix 6
It was found that the amount of gas leaked from the end of the electrode was not negligible even when phosphoric acid was impregnated in. This means that, although water repellency was not given to the electrode end, a portion with a relatively large pore size remained because it was not subjected to densification treatment, etc. It is presumed that it cannot penetrate into the part with large target pore size.
That is, with such an electrode seal structure, the wet seal function by permeation of phosphoric acid cannot be realized.
【0024】つぎに、このように構成された燃料極1と
空気極2を用い、燃料電池を組み立てて発電試験を実施
した。この際、燃料極1には水素80%と二酸化炭素2
0%との混合ガスを、空気極2には空気をそれぞれ供給
し、燃料ガスと空気の漏洩量は、それぞれの出口でガス
分析を実施して測定し、さらに、図8の(a)に示すよ
うに、各電極と相対する緻密質サイドレール12および
多孔質板9、10の四辺の中央部分には絶縁被覆熱電対
と参照極付電極(RE1〜4:燃料側参照極、RE5〜
8:空気側参照極)とを配置し、各部分の局部的な温度
と燃料側、空気側周辺部分の電気化学的電位の実測も平
行して行った。Next, a fuel cell was assembled using the fuel electrode 1 and the air electrode 2 thus constructed, and a power generation test was conducted. At this time, the fuel electrode 1 has 80% hydrogen and 2 carbon dioxide.
The mixed gas with 0% is supplied to the air electrode 2, and the air is supplied to the air electrode 2, and the leakage amounts of the fuel gas and the air are measured by performing gas analysis at the respective outlets, and further shown in (a) of FIG. As shown, in the central portions of the four sides of the dense side rails 12 and the porous plates 9 and 10 facing the respective electrodes, an insulating coating thermocouple and a reference electrode (RE1 to 4: fuel side reference electrode, RE5 to RE5).
8: Air side reference electrode), and the local temperature of each part and the electrochemical potentials of the fuel side and air side peripheral parts were also measured in parallel.
【0025】図6、図7に示す測定結果から、運転立ち
上げ直後には、電極シール性能評価試験の結果と同様
に、相当量のガス漏洩量が確認されたが、立ち上げ後十
数分間でガス漏洩量は著しく低減し、30分後にはパッ
キンシール方式の燃料電池と同等のレベルに達した。ま
た、燃料側と空気側との差圧をかえても、ガス漏洩量に
はほとんど影響しなかった。さらに、セルの出力特性
も、立ち上げ直後は少し低いが、ガス漏洩量の低減とと
もに向上し安定する結果が得られた。From the measurement results shown in FIG. 6 and FIG. 7, a considerable amount of gas leakage was confirmed just after the start-up of the operation, similar to the result of the electrode seal performance evaluation test. The amount of gas leakage was remarkably reduced, and after 30 minutes, it reached a level equivalent to that of a packing seal type fuel cell. Moreover, even if the pressure difference between the fuel side and the air side was changed, the gas leakage amount was hardly affected. Furthermore, the output characteristics of the cell were slightly low immediately after startup, but improved and stabilized with the decrease in gas leakage.
【0026】発電試験の際の緻密質サイドレール12上
の温度は立ち上げ後大きな変化はなく、電極中央部分で
の温度に比べて約10℃低いレベルに維持され、従来懸
念されていたような電極端部シールでの燃料ガスと空気
との直接接触反応による温度上昇等は認められなかっ
た。The temperature on the dense side rails 12 during the power generation test did not change significantly after the start-up, and was maintained at a level about 10 ° C. lower than the temperature at the center of the electrode, which was a concern in the past. No increase in temperature due to direct contact reaction between fuel gas and air at the electrode end seal was observed.
【0027】電気化学的電位については、立ち上げ直後
は燃料ガスと空気との差圧により不安定な挙動を示した
が、ガス漏洩量の低減とともに電位は下降して安定し
た。但し、図8の(b)に示すように、空気側参照電極
の空気流路入口および出口部分の電位だけは他の部分よ
りも高い電位に保たれた。The electrochemical potential showed unstable behavior immediately after the start-up due to the pressure difference between the fuel gas and air, but the potential dropped and became stable as the amount of gas leakage decreased. However, as shown in FIG. 8B, only the electric potentials at the air flow path inlet and outlet portions of the air-side reference electrode were kept at higher potentials than the other portions.
【0028】さらに、発電試験の発電負荷を変えて実験
を行ったが、負荷に拘わらず上記実験と同様の現象が確
認され、負荷を取らずに解放電圧状態でも同様の現象が
確認された。Further, an experiment was carried out by changing the power generation load of the power generation test, and the same phenomenon as the above experiment was confirmed regardless of the load, and the same phenomenon was also confirmed in the open voltage state without taking the load.
【0029】以上のことから、電極間のガスシール性能
が向上する理由は、以下のように推定できる。まず、立
ち上げ直後には、燃料ガス中の水素と空気中の酸素とが
電極端部の未はっ水領域にて直接接触して反応するが、
電極両端部分はその上下を緻密質サイドレール12とリ
ン酸が含浸されたマトリックス6で挟まれていて、上下
方向へのガスの逃げ道がないため、ある程度反応量が増
えると生成水蒸気の圧力が飽和水蒸気圧に達し、反応の
結果生成されるものが液体状の水に変わる。生成された
水は、マトリックス6に含浸されていたリン酸と一緒に
なり、その濃度を低減させると同時に体積の膨張を引き
起こし、はっ水処理が施されていない電極両端部分の比
較的大きな気孔径にまで容易に圧入される。即ち、立ち
上げ直後に漏洩した燃料と空気との直接反応生成物によ
り電極両端部分のシール性能が高められて、その結果一
定時間が経過した後は、この部分からの燃料ガスおよび
空気の漏洩が極めて少なくなるものと考えられ、はっ水
性が付与された触媒層での発電反応自体は電極のシール
性能の変化には無関係であるものと推定される。From the above, the reason why the gas sealing performance between the electrodes is improved can be estimated as follows. First, immediately after startup, hydrogen in the fuel gas and oxygen in the air directly contact and react in the non-water-repellent region at the electrode end,
Both ends of the electrode are sandwiched between the dense side rails 12 and the matrix 6 impregnated with phosphoric acid at the upper and lower sides, and there is no escape path for the gas in the vertical direction, so the pressure of the generated steam becomes saturated when the reaction amount increases to some extent. The water vapor pressure is reached and what is produced as a result of the reaction is transformed into liquid water. The generated water is combined with the phosphoric acid impregnated in the matrix 6 to reduce its concentration and at the same time cause the volume to expand. Easy to press down to the hole diameter. That is, the direct reaction product of the fuel and the air leaked immediately after the start-up enhances the sealing performance at both end portions of the electrode, and as a result, after a certain period of time, the leakage of fuel gas and air from this portion is prevented. It is considered to be extremely small, and it is presumed that the power generation reaction itself in the catalyst layer provided with water repellency is irrelevant to the change in the sealing performance of the electrode.
【0030】なお、図4に示した電極シール性能試験に
おいて、燃料極側には水素80%と二酸化炭素20%と
の混合ガスを、空気極側には空気を供給したところ、発
電試験の場合と同様な現象が起こり、一定時間経過後に
は電極シール性能が向上することが確認できた。In the electrode seal performance test shown in FIG. 4, a mixed gas of hydrogen 80% and carbon dioxide 20% was supplied to the fuel electrode side, and air was supplied to the air electrode side. It was confirmed that the same phenomenon as above occurred and the electrode sealing performance was improved after a certain period of time.
【0031】このように、上記実施例1によれば、セパ
レータ7と同一平面寸法で燃料極1と空気極2とを形成
し、燃料極1および空気極2のそれぞれの多孔性基材5
の面内全域に燃料極触媒層3および空気極触媒層4を塗
布形成し、この燃料極1には、燃料ガス流路8に平行な
両側部分で、その幅が緻密質サイドレール12と同程度
の領域において、未はっ水領域3bを形成し、さらに空
気極2には、空気流路10に平行な両側部分で、その幅
が緻密質サイドレール12と同程度の領域において、未
はっ水領域4bを形成しているので、独立したシール部
材を用いることなく、また電極端部に特別なシール部分
を設けることなく、燃料電池運転中の電極周辺部分での
シール性能を維持することができるという効果が得られ
る。As described above, according to the first embodiment, the fuel electrode 1 and the air electrode 2 are formed in the same plane size as the separator 7, and the porous base material 5 of each of the fuel electrode 1 and the air electrode 2 is formed.
A fuel electrode catalyst layer 3 and an air electrode catalyst layer 4 are formed by coating all over the surface of the fuel electrode 1, and the width of the fuel electrode 1 is the same as that of the dense side rails 12 on both side portions parallel to the fuel gas passage 8. The water repellent region 3b is formed in the region of about 2 mm, and the air electrode 2 is formed on both side portions parallel to the air flow path 10 in the region where the width thereof is the same as that of the dense side rail 12. Since the water-repellent region 4b is formed, it is possible to maintain the sealing performance in the electrode peripheral portion during the fuel cell operation without using a separate sealing member and without providing a special sealing portion at the electrode end. The effect of being able to do is obtained.
【0032】また、独立したシール部材を用いないの
で、電極部材点数の増加を抑え、セルの積層作業性を向
上でき、さらに積み精度も向上することができる。Further, since an independent seal member is not used, an increase in the number of electrode members can be suppressed, cell stacking workability can be improved, and stacking accuracy can also be improved.
【0033】さらに、はっ水処理等の通常の電極の製造
方法で実施される処理工程以外の処理工程を必要としな
いので、電極の製造作業性が向上できる。Further, since no processing steps other than the processing steps carried out in the ordinary electrode manufacturing method such as water repellency treatment are required, the workability of manufacturing the electrodes can be improved.
【0034】実施例2.上記実施例1では、燃料極1お
よび空気極2の電極両端部分の触媒層を未はっ水領域3
b、4bとし、未はっ水領域3b、4bで電極シール部
分を構成するものとしているが、この実施例2では、燃
料極1あるいは空気極2のいずれかの電極にのみ未はっ
水領域を設けるものとし、同様の効果を奏する。Example 2. In the above-described Example 1, the catalyst layers at both ends of the fuel electrode 1 and the air electrode 2 are formed in the non-water-repellent region 3
b and 4b, and the non-water-repellent regions 3b and 4b constitute the electrode seal portion. However, in the second embodiment, the non-water-repellent region is formed only on either the fuel electrode 1 or the air electrode 2. Is provided, and the same effect is obtained.
【0035】実施例3.上記実施例1、2では、燃料極
1および空気極2の電極両端部分の触媒層を未はっ水領
域3b、4bとするものとしているが、この実施例3で
は、図9、図10に示すように、燃料極1および空気極
2の電極周辺部分の触媒層を未はっ水領域3b、4bと
するものとし、同様の効果を奏する。Example 3. In Examples 1 and 2 described above, the catalyst layers at both electrode end portions of the fuel electrode 1 and the air electrode 2 are assumed to be the non-water-repellent regions 3b and 4b. As shown, the catalyst layers around the electrodes of the fuel electrode 1 and the air electrode 2 are set to the non-water-repellent regions 3b and 4b, and the same effect is obtained.
【0036】実施例4.上記実施例1〜3では、燃料極
1および空気極2の電極両端部分の未はっ水領域3b、
4bには、はっ水領域3a、4aと同じ触媒を塗布形成
するものとしているが、この実施例4では、未はっ水領
域3b、4bに高密度化処理を施すものとし、シール性
能がより向上し安定化する効果が得られる。Example 4. In Examples 1 to 3 above, the non-water-repellent regions 3b at both ends of the electrodes of the fuel electrode 1 and the air electrode 2,
4b is formed by applying the same catalyst as in the water-repellent regions 3a and 4a, but in the fourth embodiment, the non-water-repellent regions 3b and 4b are subjected to the densification treatment, and the sealing performance is improved. The effect of further improving and stabilizing is obtained.
【0037】なお、上記実施例1〜4では、燃料極1お
よび空気極2の触媒層の未はっ水領域3b、4bの幅を
緻密質サイドレール12とほぼ同等の幅とするものとし
て説明しているが、未はっ水領域3b、4bの幅は緻密
質サイドレール12の幅に関係なく電極シール性能が許
せる範囲内で狭くすることができる。In Examples 1 to 4 described above, the width of the non-water-repellent regions 3b and 4b of the catalyst layers of the fuel electrode 1 and the air electrode 2 is set to be substantially equal to that of the dense side rail 12. However, the width of the non-water-repellent regions 3b and 4b can be narrowed within the range where the electrode sealing performance is allowed, regardless of the width of the dense side rail 12.
【0038】また、上記実施例1〜4では、多孔性基材
5に触媒塗布後加熱焼成する際に、マスキングを施して
その部分の温度をフッ素樹脂の融点以下に保つようにし
て未はっ水領域3b、4bを形成するものとして説明し
ているが、はっ水領域を形成する部分には、フッ素樹脂
をバインダ材とし、未はっ水領域を形成する部分には、
はっ水性を有しないバインダ材、例えばポリエーテルサ
ルフォン(PES)樹脂を用いても、同様の効果を奏す
る。Further, in the above Examples 1 to 4, when the porous substrate 5 was coated with the catalyst and then heated and baked, masking was performed to keep the temperature of the portion below the melting point of the fluororesin. Although the description has been made assuming that the water regions 3b and 4b are formed, a fluororesin is used as a binder material in the portion forming the water repellent region, and
Even if a binder material having no water repellency, for example, a polyether sulfone (PES) resin is used, the same effect can be obtained.
【0039】さらに、上記実施例1〜4では、多孔性基
材5の全面に触媒を塗布形成するものとして説明してい
るが、多孔性基材5のはっ水領域に触媒を塗布形成し、
未はっ水領域には触媒以外の他の材料、例えばはっ水性
の低いカーボンブラック、SiCを塗布してもよく、白
金を含有し高価な触媒の使用量を低減し、コスト低減を
図ることができる。Furthermore, in the above-mentioned Examples 1 to 4, the catalyst is applied and formed on the entire surface of the porous substrate 5, but the catalyst is applied and formed on the water repellent region of the porous substrate 5. ,
Materials other than catalysts, such as carbon black or SiC with low water repellency, may be applied to the non-water-repellent region, and the amount of expensive catalyst containing platinum is reduced to reduce the cost. You can
【0040】実施例5.図11はこの発明の第2の発明
に係る一実施例を示すリン酸形燃料電池の電極シール構
造の要部断面図、図12の(a)、(b)はそれぞれこ
の発明の実施例5における燃料極の単品状態を示す平面
図および断面図、図13の(a)、(b)はそれぞれこ
の発明の実施例5における空気極の単品状態を示す平面
図および断面図である。図において、16は空気極2の
燃料ガス流路8に平行な両端部分に空気極触媒層4に代
えて配置された、腐食防止層としてのカーボンブラック
層である。Example 5. FIG. 11 is a sectional view of a main part of an electrode seal structure for a phosphoric acid fuel cell showing an embodiment according to the second invention of the present invention, and FIGS. 12 (a) and 12 (b) show Embodiment 5 of the present invention. 13A and 13B are a plan view and a cross-sectional view showing the individual state of the fuel electrode in FIG. 13, and FIGS. 13A and 13B are a plan view and a sectional view showing the single-state state of the air electrode in the fifth embodiment of the present invention, respectively. In the figure, reference numeral 16 denotes a carbon black layer as a corrosion prevention layer, which is arranged in place of the air electrode catalyst layer 4 at both end portions of the air electrode 2 parallel to the fuel gas passage 8.
【0041】ここで、上記実施例5では、燃料極1およ
び空気極2は、セル外形サイズ、即ちセパレータ7と同
一平面寸法に形成され、燃料極触媒層3が多孔性基材5
の面内全域に塗布形成されて構成する燃料極1には、燃
料ガス流路8に平行な両端部分で、その幅が緻密質サイ
ドレール12と同程度の領域において、未はっ水領域3
bが形成されている。Here, in the fifth embodiment, the fuel electrode 1 and the air electrode 2 are formed in the cell outer size, that is, in the same plane size as the separator 7, and the fuel electrode catalyst layer 3 is the porous substrate 5.
In the fuel electrode 1 formed by coating and forming the entire surface of the surface of the fuel electrode, the non-water-repellent region 3 is formed in both end portions parallel to the fuel gas flow passage 8 and in a region where the width thereof is similar to that of the dense side rail 12.
b is formed.
【0042】一方、空気極2を構成する多孔性基材5の
燃料ガス流路8に平行な両端部分には、緻密質サイドレ
ール12と同程度の幅でカーボンブラック層16が塗布
され、その内側部分には、空気極触媒層4が塗布されて
いる。この空気極触媒層4およびカーボンブラック層1
6は同時作業で多孔性基材5に塗布され、空気極触媒層
4とカーボンブラック層16との段差のない全面均一な
厚みの空気極2となっている。さらに、この空気極2に
は、空気流路10に平行な両側部分で、その幅が緻密質
サイドレール12と同程度の領域において、未はっ水領
域4bが形成されている。On the other hand, a carbon black layer 16 having a width similar to that of the dense side rails 12 is applied to both end portions of the porous base material 5 forming the air electrode 2 in parallel with the fuel gas flow path 8. The air electrode catalyst layer 4 is applied to the inner portion. The air electrode catalyst layer 4 and the carbon black layer 1
6 is applied simultaneously to the porous substrate 5 to form the air electrode 2 having a uniform thickness over the entire surface without any step between the air electrode catalyst layer 4 and the carbon black layer 16. Further, the air electrode 2 is provided with water-repellent regions 4b in both side portions parallel to the air flow path 10 in a region whose width is about the same as that of the dense side rail 12.
【0043】燃料極1および空気極2におけるはっ水処
理は、上記実施例1と同様に、フッ素樹脂をバインダ材
として用い、未はっ水領域にマスキングを施してフッ素
樹脂の融点以上に加熱処理して行っている。また、カー
ボンブラック層16には、はっ水処理を施していない。In the water repellent treatment at the fuel electrode 1 and the air electrode 2, the fluororesin is used as the binder material, and the water repellent region is masked and heated above the melting point of the fluororesin, as in the first embodiment. I'm processing and going. Further, the carbon black layer 16 is not subjected to water repellent treatment.
【0044】このように構成された燃料極1および空気
極2を用い、図4に示した電極シール性能試験を実施し
た。まず、燃料極側にはメタンを、空気極側にはキャリ
アガスとしての窒素を供給した場合、電極端部からのガ
ス漏洩量が多く、マトリックス6にリン酸を含浸させて
た状態でも、電極端部からのガス漏洩量は無視できない
レベルであった。ついで、燃料極側には水素80%と二
酸化炭素20%との混合ガスを、空気極側には空気を供
給した場合、最初の十数分間は、電極シールからのガス
漏洩量は多いが、一定時間経過後には、電極シール性能
が向上することが確認できた。Using the thus constructed fuel electrode 1 and air electrode 2, the electrode seal performance test shown in FIG. 4 was carried out. First, when methane was supplied to the fuel electrode side and nitrogen as the carrier gas was supplied to the air electrode side, the amount of gas leaked from the electrode end was large, and even if the matrix 6 was impregnated with phosphoric acid, the The amount of gas leaked from the extreme part was at a level that cannot be ignored. Then, when a mixed gas of 80% hydrogen and 20% carbon dioxide is supplied to the fuel electrode side and air is supplied to the air electrode side, the amount of gas leakage from the electrode seal is large for the first ten minutes, It was confirmed that the electrode sealing performance was improved after a certain period of time.
【0045】ところで、電極間でガスシール性能が向上
する理由は、上記実施例1と同様と推定される。即ち、
最初の十数分間に漏洩した燃料と空気との直接反応生成
物により、未はっ水触媒層部分およびカーボンブラック
層部分に液体状の水が生成され、マトリックス6中のリ
ン酸が薄められて膨張して電極のこれらの部分に圧入浸
透することにより、シール性能が高められる。その結
果、一定時間経過後は、この部分からの燃料ガスおよび
空気の漏洩が極めて少なくなるものと考えられる。By the way, the reason why the gas sealing performance between the electrodes is improved is presumed to be the same as in the first embodiment. That is,
The direct reaction product of the fuel and air that leaked during the first ten or more minutes produced liquid water in the non-water-repellent catalyst layer portion and the carbon black layer portion, and the phosphoric acid in the matrix 6 was diluted. By expanding and press-fitting into these parts of the electrode, the sealing performance is enhanced. As a result, it is considered that the leakage of fuel gas and air from this portion becomes extremely small after a certain period of time.
【0046】つぎに、このように構成された燃料電池1
と空気極2を用い、燃料電池を組み立てて発電試験を実
施した。この際、上記実施例1と同様に、燃料極1には
水素80%と二酸化炭素20%との混合ガスを、空気極
2には空気をそれぞれ供給し、燃料ガスと空気の漏洩量
は、それぞれの出口でガス分析を実施して測定し、さら
に、図14の(a)に示すように、各電極と相対する緻
密質サイドレール12および多孔質板9、10の四辺の
中央部分には絶縁被覆熱電対と参照極付電極(RE1〜
4:燃料側参照極、RE5〜8:空気側参照極)とを配
置し、各部分の局部的な温度と燃料側、空気側周辺部分
の電気化学的電位の実測も平行して行った。Next, the fuel cell 1 thus constructed
A fuel cell was assembled using the and the air electrode 2 and a power generation test was performed. At this time, similarly to the first embodiment, a mixed gas of 80% hydrogen and 20% carbon dioxide was supplied to the fuel electrode 1 and air was supplied to the air electrode 2, and the leakage amount of the fuel gas and the air was Gas analysis was carried out at each outlet for measurement, and further, as shown in FIG. 14 (a), the dense side rails 12 and the porous plates 9 and 10 facing the respective electrodes had a central portion on four sides. Insulation coated thermocouple and reference electrode (RE1
(4: fuel-side reference electrode, RE5-8: air-side reference electrode) were arranged, and the local temperature of each part and the electrochemical potentials of the fuel-side and air-side peripheral parts were also measured in parallel.
【0047】発電試験の結果から、運転立ち上げ直後に
は、上記実施例1と同様に、相当量のガス漏洩量が確認
されたが、立ち上げ後十数分間でガス漏洩量は著しく低
減し、30分後にはパッキンシール方式の燃料電池と同
等のレベルに達した。また、燃料側と空気側との差圧を
かえても、ガス漏洩量には影響しない。さらに、セルの
出力特性も、立ち上げ直後は少し低いが、ガス漏洩量の
低減とともに向上し安定する結果が得られた。From the results of the power generation test, a considerable amount of gas leakage was confirmed immediately after the start of operation, as in Example 1, but the amount of gas leakage was remarkably reduced within 10 minutes after the start of operation. After 30 minutes, it reached a level equivalent to that of a packing seal type fuel cell. Further, even if the pressure difference between the fuel side and the air side is changed, the gas leakage amount is not affected. Furthermore, the output characteristics of the cell were slightly low immediately after startup, but improved and stabilized with the decrease in gas leakage.
【0048】発電試験の際の緻密質サイドレール12上
の温度は、上記実施例1と同様に、立ち上げ後大きな変
化はなく、電極中央部分での温度に比べて約10℃低い
レベルに維持され、従来懸念されていたような電極端部
シールでの燃料ガスと空気との直接接触反応による温度
上昇等は認められなかった。The temperature on the dense side rails 12 during the power generation test did not change much after the start-up, and was maintained at a level about 10 ° C. lower than the temperature at the center of the electrode, as in Example 1 above. However, the temperature rise due to the direct contact reaction between the fuel gas and the air at the electrode end seal, which has been a concern in the past, was not recognized.
【0049】電気化学的電位については、上記実施例1
と同様に、立ち上げ直後は燃料ガスと空気との差圧によ
り不安定な挙動を示したが、図14の(b)に示すよう
に、ガス漏洩量の低減とともに電位は下降して安定し
た。しかしながら、空気側参照電極の空気流路入口およ
び出口部分の電位(即ち、燃料ガス流路8と平行な空気
極2の両端のカーボンブラック層16部分の上部)は、
立ち上げ直後から常に低い値で安定していた。Regarding the electrochemical potential, the above-mentioned Example 1 was used.
Similarly to the above, immediately after the start-up, an unstable behavior was exhibited due to the pressure difference between the fuel gas and the air, but as shown in FIG. 14B, the potential decreased and became stable as the gas leakage amount decreased. .. However, the potentials of the air flow path inlet and outlet of the air side reference electrode (that is, the upper portions of the carbon black layer 16 parts at both ends of the air electrode 2 parallel to the fuel gas flow path 8) are
Immediately after launch, it was always stable at a low value.
【0050】この電気化学的電位が高くなる理由は、光
田等がISE40th Meeting Abs.No.b1-18-01-13-G(1889)で
説明しているように、燃料極1側に充分な水素が供給さ
れず、電解質中のプロトン(H+)が不足状態になっ
て、空気極触媒層4の下でプロトンと酸素と電子とによ
る反応が起きることに起因する。上記実施例1におい
て、一定時間経過後も空気側の流路入口および出口部分
の電位が高めに維持されるのは、この部分の反対側(つ
まり、燃料極1の燃料ガス流路8と平行な両端部分)
で、ガスシール性の向上とともに水素の供給が出来なく
なり、この部分の上部のマトリックス6のリン酸中のプ
ロトンが不足状態になっているにも拘わらず、空気極2
側は空気流路10の入口および出口部分に相当するため
に空気極触媒層4の下でプロトンと酸素と電子とによる
反応が起きることによる。The reason why this electrochemical potential becomes high is that, as Mitsuda et al. Explained in ISE 40th Meeting Abs. No. b1-18-01-13-G (1889), it is sufficient for the fuel electrode 1 side. This is because hydrogen is not supplied and protons (H + ) in the electrolyte become insufficient, so that a reaction between protons, oxygen and electrons occurs under the air electrode catalyst layer 4. In the first embodiment, the potentials of the inlet and outlet of the flow passage on the air side are maintained at a high level even after the lapse of a certain period of time, that is, on the opposite side (that is, parallel to the fuel gas flow passage 8 of the fuel electrode 1) (Both ends)
With the improvement of the gas sealability, it becomes impossible to supply hydrogen, and although the protons in the phosphoric acid of the matrix 6 in the upper part of this portion are insufficient, the air electrode 2
Since the side corresponds to the inlet and outlet portions of the air flow path 10, a reaction between protons, oxygen and electrons occurs under the air electrode catalyst layer 4.
【0051】一方、上記実施例5では、空気極2の空気
流路10の入口および出口部分に、空気極触媒層4の代
わりにカーボンブラック層16が配置されているので、
プロトンと酸素と電子との反応が起こらず、電気化学的
電位が常に低い電位に保たれる。一般に、電気化学的電
位は、カーボン腐食の観点から1.0v以下に保つこと
が得策と考えられ、この点から上記実施例5では、耐食
性に優れている。On the other hand, in the fifth embodiment, since the carbon black layer 16 is arranged at the inlet and the outlet of the air passage 10 of the air electrode 2 instead of the air electrode catalyst layer 4,
The reaction between protons, oxygen and electrons does not occur, and the electrochemical potential is always kept low. In general, it is considered to be a good idea to keep the electrochemical potential at 1.0 v or less from the viewpoint of carbon corrosion, and from this point, Example 5 has excellent corrosion resistance.
【0052】このように、上記実施例5によれば、セパ
レータ7と同一平面寸法で燃料極1と空気極2とを形成
し、多孔性基材5の面内全域に燃料極触媒層3を塗布形
成してなる燃料極1には、燃料ガス流路8に平行な両側
部分で、その幅が緻密質サイドレール12と同程度の領
域において、未はっ水領域3bを形成し、さらに多孔性
基材5の燃料ガス流路8と平行な両端部分にカーボンブ
ラック層16を塗布形成し、他の領域に空気極触媒層4
を塗布形成してなる空気極2には、空気流路10に平行
な両側部分で、その幅が緻密質サイドレール12と同程
度の領域において、未はっ水領域4bを形成しているの
で、独立したシール部材を用いることなく、また電極端
部にシール部分を設けることなく、燃料電池運転中の電
極周辺部分でのシール性能を維持することができるとい
う効果が得られる。As described above, according to the fifth embodiment, the fuel electrode 1 and the air electrode 2 are formed in the same plane size as the separator 7, and the fuel electrode catalyst layer 3 is formed over the entire surface of the porous substrate 5. In the fuel electrode 1 formed by coating, the non-water-repellent region 3b is formed in both side portions parallel to the fuel gas flow channel 8 and the width thereof is about the same as that of the dense side rail 12, and the porous electrode 3 is further porous. A carbon black layer 16 is formed by coating on both end portions of the organic base material 5 parallel to the fuel gas flow channel 8, and the air electrode catalyst layer 4 is formed on other areas.
In the air electrode 2 formed by coating, the non-water-repellent region 4b is formed in both side portions parallel to the air flow path 10 and in the region whose width is about the same as the dense side rail 12. It is possible to obtain the effect that the sealing performance can be maintained in the peripheral portion of the electrode during the operation of the fuel cell without using an independent sealing member or providing a sealing portion at the electrode end portion.
【0053】また、独立したシール部材を用いないの
で、電極部材点数の増加を抑え、セルの積層作業性を向
上でき、さらに積み精度も向上することができる。Further, since an independent seal member is not used, it is possible to suppress an increase in the number of electrode members, improve the workability of stacking cells, and further improve the stacking accuracy.
【0054】さらに、はっ水処理等の通常の電極の製造
方法で実施される処理工程以外の処理工程を必要としな
いので、電極の製造作業性が向上できる。Furthermore, since no processing steps other than the processing steps carried out in the usual electrode manufacturing method such as water repellency treatment are required, the workability of manufacturing the electrodes can be improved.
【0055】さらにまた、空気極2の燃料ガス流路8と
平行な両端部分にカーボンブラック層16を配置してい
るので、この部分での電気化学的電位を低減でき、カー
ボン腐食対策が強化でき、長期的信頼性を向上できる。Furthermore, since the carbon black layers 16 are arranged at both end portions of the air electrode 2 which are parallel to the fuel gas flow path 8, the electrochemical potential at these portions can be reduced and the carbon corrosion countermeasure can be strengthened. , Can improve long-term reliability.
【0056】実施例6.上記実施例5では、空気極2の
燃料ガス流路8と平行な両端部分に、空気極触媒層4に
代えカーボンブラック層16を配置するものとしている
が、この実施例6では、同時に燃料極1の燃料ガス流路
8と平行な両端部分に、燃料極触媒層3に代えカーボン
ブラック層16を配置するものとし、同様の効果を奏す
る。Example 6. In the fifth embodiment, the carbon black layers 16 are arranged in place of the air electrode catalyst layers 4 at both end portions of the air electrode 2 which are parallel to the fuel gas flow channel 8. However, in the sixth embodiment, the fuel electrodes are simultaneously formed. The carbon black layer 16 is arranged instead of the fuel electrode catalyst layer 3 at both end portions parallel to the fuel gas passage 8 of No. 1, and the same effect is obtained.
【0057】実施例7.上記実施例5では、空気極2の
燃料ガス流路8と平行な両端部分のみに、空気極触媒層
4に代えカーボンブラック層16を配置するものとして
いるが、この実施例7では、空気極1の周辺部分に、空
気極触媒層4に代えカーボンブラック層16を配置する
ものとし、電極の製造作業性が若干低下するも、白金を
含有する高価な触媒の使用量を低減し、コストを低減す
ることができる。Example 7. In the fifth embodiment, the carbon black layer 16 is arranged instead of the air electrode catalyst layer 4 only at both end portions of the air electrode 2 which are parallel to the fuel gas flow path 8. However, in the seventh embodiment, the air electrode is formed. The carbon black layer 16 is arranged in place of the air electrode catalyst layer 4 in the peripheral portion of No. 1, and although the manufacturing workability of the electrode is slightly lowered, the amount of expensive platinum-containing catalyst used is reduced and the cost is reduced. It can be reduced.
【0058】実施例8.上記実施例5では、カーボンブ
ラック層16をはっ水処理しないものとしているが、こ
の実施例8では、本来この部分は電極のシール性には関
与しない領域であることから、カーボンブラック層16
にバインダ材としてフッ素樹脂を用い、はっ水処理する
ものとし、カーボンブラック層16の結着性を向上さ
せ、電極の製造作業性を向上することができる。Example 8. In the above-mentioned fifth embodiment, the carbon black layer 16 is not subjected to the water repellent treatment, but in this eighth embodiment, this portion is originally a region that is not involved in the sealing property of the electrode.
Fluorine resin is used as the binder material for the water repellent treatment to improve the binding property of the carbon black layer 16 and the workability of manufacturing the electrode.
【0059】なお、上記実施例5〜8では、触媒層に代
えて腐食防止層としてのカーボンブラック層16を配置
するものとして説明しているが、腐食防止層としての材
料はカーボンブラックに限定されるものではなく、白金
等の貴金属を含有せず耐熱リン酸性の材料であればよ
く、例えばSiCを用いてもよい。In the above-mentioned Examples 5 to 8, the carbon black layer 16 as the corrosion preventing layer is arranged instead of the catalyst layer, but the material for the corrosion preventing layer is limited to carbon black. The material is not limited to this, and may be a material that does not contain a precious metal such as platinum and is heat-resistant phosphoric acid, and for example, SiC may be used.
【0060】[0060]
【発明の効果】この発明は、以上説明したように構成さ
れているので、以下に記載されるような効果を奏する。Since the present invention is constructed as described above, it has the following effects.
【0061】この発明の第1の発明によれば、燃料極お
よび空気極は、セパレータと同等の外形を有し、かつ燃
料極および空気極の少なくとも一方の極の両端部分のは
っ水性を低減させ、はっ水性を低減させた両端部分を電
極シール部分としているので、他に独立した電極周辺シ
ール等が不要となり、積層部品点数を著しく低減し、セ
ルの積層作業性が向上できるとともに積み精度も向上で
き、かつ、電極処理工程が特殊な処理工程を必要とせ
ず、電極の製造作業性が向上でき、結果として、燃料電
池の製作の中で大きな作業ウエイトを占めている電極製
造作業とセル積層作業が極めてシンプル化され、量産作
業性に優れ、かつ、生産コストを低減できる。According to the first aspect of the present invention, the fuel electrode and the air electrode have the same outer shape as the separator, and the water repellency of both ends of at least one of the fuel electrode and the air electrode is reduced. Since both ends with reduced water repellency are used as electrode seal parts, no separate electrode peripheral seals are required, significantly reducing the number of laminated parts, improving the stacking workability of cells, and stacking accuracy. In addition, the electrode manufacturing process does not require a special processing process, and the electrode manufacturing workability can be improved. As a result, the electrode manufacturing work and the cell which occupy a large work weight in the production of the fuel cell. The stacking work is extremely simplified, the workability in mass production is excellent, and the production cost can be reduced.
【0062】また、この発明の第2の発明によれば、燃
料極および空気極は、セパレータと同等の外形を有し、
空気極の燃料ガス流路に平行な両端部分に触媒層に代え
て腐食防止層を設けているので、空気極の空気流路の入
口および出口部分における電気化学的電位が低く保たれ
てカーボン腐食が抑制され、電極の長期的信頼性を向上
できる。According to the second aspect of the present invention, the fuel electrode and the air electrode have the same outer shape as the separator,
Since a corrosion prevention layer is provided in place of the catalyst layer at both ends of the air electrode parallel to the fuel gas flow path, the electrochemical potential at the inlet and outlet of the air electrode air flow path is kept low and carbon corrosion Is suppressed, and the long-term reliability of the electrode can be improved.
【図1】この発明の実施例1を示すリン酸形燃料電池の
電極シール構造の要部断面図である。FIG. 1 is a sectional view of an essential part of an electrode seal structure for a phosphoric acid fuel cell, showing Embodiment 1 of the present invention.
【図2】(a)、(b)はそれぞれこの発明の実施例1
における燃料極の単品状態を示す平面図および断面図で
ある。2A and 2B are respectively Embodiment 1 of the present invention.
FIG. 4 is a plan view and a cross-sectional view showing a single state of the fuel electrode in FIG.
【図3】(a)、(b)はそれぞれこの発明の実施例1
における空気極の単品状態を示す平面図および断面図で
ある。3 (a) and 3 (b) are each a first embodiment of the present invention.
FIG. 3 is a plan view and a cross-sectional view showing a single item state of the air electrode in FIG.
【図4】この発明の実施例1のリン酸形燃料電池におけ
る電極のシール性能試験の模式図である。FIG. 4 is a schematic diagram of an electrode sealing performance test in the phosphoric acid fuel cell of Example 1 of the present invention.
【図5】この発明の実施例1のリン酸形燃料電池の電極
シール性能試験におけるメタン圧力と単位シール長さ当
たりのメタン漏れ量との関係を示すグラフである。FIG. 5 is a graph showing the relationship between the methane pressure and the amount of methane leakage per unit seal length in the electrode seal performance test of the phosphoric acid fuel cell of Example 1 of the present invention.
【図6】この発明の実施例1のリン酸形燃料電池の発電
試験における燃料ガス出口と空気出口との差圧と単位シ
ール長さ当たりの燃料ガス漏れ量との関係を示すグラフ
である。FIG. 6 is a graph showing the relationship between the differential pressure between the fuel gas outlet and the air outlet and the fuel gas leakage amount per unit seal length in the power generation test of the phosphoric acid fuel cell of Example 1 of the present invention.
【図7】この発明の実施例1のリン酸形燃料電池の発電
試験における単位シール長さ当たりの燃料ガス漏れ量の
経時変化を示すグラフである。FIG. 7 is a graph showing the change over time in the fuel gas leakage amount per unit seal length in the power generation test of the phosphoric acid fuel cell of Example 1 of the present invention.
【図8】(a)はこの発明の実施例1のリン酸形燃料電
池における発電試験時の電気化学的電位を測定するため
の参照極配置を示す分解斜視図であり、(b)は各参照
極における電気化学的電位を示すグラフである。FIG. 8A is an exploded perspective view showing a reference electrode arrangement for measuring an electrochemical potential during a power generation test in the phosphoric acid fuel cell of Example 1 of the present invention, and FIG. It is a graph which shows the electrochemical potential in a reference electrode.
【図9】(a)、(b)はそれぞれこの発明の実施例2
における燃料極の単品状態を示す平面図および断面図で
ある。9 (a) and 9 (b) are each a second embodiment of the present invention.
FIG. 4 is a plan view and a cross-sectional view showing a single state of the fuel electrode in FIG.
【図10】(a)、(b)はそれぞれこの発明の実施例
2における空気極の単品状態を示す平面図および断面図
である。10 (a) and 10 (b) are respectively a plan view and a cross-sectional view showing a single-piece state of an air electrode in Example 2 of the present invention.
【図11】この発明の実施例5を示すリン酸形燃料電池
の電極シール構造の要部断面図である。FIG. 11 is a sectional view of an essential part of an electrode seal structure for a phosphoric acid fuel cell, showing Embodiment 5 of the present invention.
【図12】(a)、(b)はそれぞれこの発明の実施例
5における燃料極の単品状態を示す平面図および断面図
である。12 (a) and 12 (b) are a plan view and a sectional view, respectively, showing a single fuel electrode state in a fifth embodiment of the present invention.
【図13】(a)、(b)はそれぞれこの発明の実施例
5における空気極の単品状態を示す平面図および断面図
である。13 (a) and 13 (b) are respectively a plan view and a cross-sectional view showing a single-piece state of an air electrode in Embodiment 5 of the present invention.
【図14】(a)はこの発明の実施例5のリン酸形燃料
電池における発電試験時の電気化学的電位を測定するた
めの参照極配置を示す分解斜視図であり、(b)は各参
照極における電気化学的電位を示すグラフである。14A is an exploded perspective view showing a reference electrode arrangement for measuring an electrochemical potential during a power generation test in a phosphoric acid fuel cell of Example 5 of the present invention, and FIG. It is a graph which shows the electrochemical potential in a reference electrode.
【図15】従来のリン酸形燃料電池における電極シール
構造の一例を示す要部断面図である。FIG. 15 is a cross-sectional view of essential parts showing an example of an electrode seal structure in a conventional phosphoric acid fuel cell.
【図16】従来のリン酸形燃料電池における電極シール
構造の他の例を示す要部断面図である。FIG. 16 is a cross-sectional view of essential parts showing another example of the electrode seal structure in the conventional phosphoric acid fuel cell.
【図17】従来のリン酸形燃料電池における電極シール
構造のさらに他の例を示す要部断面図である。FIG. 17 is a cross-sectional view of a main part showing still another example of the electrode seal structure in the conventional phosphoric acid fuel cell.
1 燃料極 2 空気極 3b 未はっ水領域 4 空気極触媒層 4b 未はっ水領域 6 マトリックス 7 セパレータ 8 燃料ガス流路 10 空気流路 16 カーボンブラック層(腐食防止層) 1 Fuel electrode 2 Air electrode 3b Non-water-repellent area 4 Air electrode catalyst layer 4b Non-water-repellent area 6 Matrix 7 Separator 8 Fuel gas flow path 10 Air flow path 16 Carbon black layer (corrosion prevention layer)
Claims (2)
保持するマトリックスと、燃料ガス流路と、空気流路
と、両流路を分離するセパレータとを備えたリン酸形燃
料電池において、前記燃料極および前記空気極は、前記
セパレータと同等の外形を有し、かつ前記燃料極および
前記空気極の少なくとも一方の極の両端部分のはっ水性
を低減させ、はっ水性を低減させた前記両端部分を電極
シール部分としたことを特徴とするリン酸形燃料電池。1. A phosphoric acid fuel cell comprising a fuel electrode, an air electrode, a matrix for holding an electrolyte between both electrodes, a fuel gas channel, an air channel, and a separator separating the both channels. In, the fuel electrode and the air electrode have the same outer shape as the separator, and reduce the water repellency of both ends of at least one of the fuel electrode and the air electrode, and reduce the water repellency. A phosphoric acid fuel cell, characterized in that the both ends thus formed are electrode sealing parts.
保持するマトリックスと、燃料ガス流路と、空気流路
と、両流路を分離するセパレータとを備えたリン酸形燃
料電池において、前記燃料極および前記空気極は、前記
セパレータと同等の外形を有し、前記空気極は、前記燃
料ガス流路と平行な両端部分に触媒層に代えて腐食防止
層を設けたことを特徴とするリン酸形燃料電池。2. A phosphoric acid fuel cell comprising a fuel electrode, an air electrode, a matrix for holding an electrolyte between both electrodes, a fuel gas channel, an air channel, and a separator separating the both channels. In the above, the fuel electrode and the air electrode have the same outer shape as the separator, and the air electrode is provided with a corrosion prevention layer instead of the catalyst layer at both end portions parallel to the fuel gas flow path. Characteristic phosphoric acid fuel cell.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3338480A JPH05174849A (en) | 1991-12-20 | 1991-12-20 | Phosphoric acid type fuel cell |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3338480A JPH05174849A (en) | 1991-12-20 | 1991-12-20 | Phosphoric acid type fuel cell |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH05174849A true JPH05174849A (en) | 1993-07-13 |
Family
ID=18318553
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP3338480A Pending JPH05174849A (en) | 1991-12-20 | 1991-12-20 | Phosphoric acid type fuel cell |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH05174849A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090305108A1 (en) * | 2006-03-01 | 2009-12-10 | Kabushikikaisha Equos Research Co., Ltd. | Fuel Cell Device |
-
1991
- 1991-12-20 JP JP3338480A patent/JPH05174849A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090305108A1 (en) * | 2006-03-01 | 2009-12-10 | Kabushikikaisha Equos Research Co., Ltd. | Fuel Cell Device |
US8197986B2 (en) * | 2006-03-01 | 2012-06-12 | Kabushikikaisha Equos Research | Fuel cell device |
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